Surface-ripened cheese product

ABSTRACT

The invention provides a surface-ripened cheese product prepared from a natural cheese base, and having extended shelf life; the natural cheese base is preferably selected from English types, eyed types, Italian types, Danish types, and reduced fat or lower fat varieties of any of same. A surface-ripening culture, preferably Penicillium candidum or Penicillium camemberti, is appli to the outside surface of a natural cheese base, and incubated under controlled conditions.

This invention relates to a surface-ripened cheese product, and tomethods for production of same. In particular, the invention relates toa surface-ripened cheese product produced from a stable natural cheesebase.

BACKGROUND OF THE INVENTION

Surface-ripened cheese products are of considerable economic importance,and command a significant and increasing share of the natural cheesemarket.

Traditionally, the surface-ripening culture plays an important role inthe maturation and development of the cheese. The culture alsocontributes to the rapid breakdown and short shelf life of thesecheeses.

German Utility Model (Gebrauchsmuster) No. 8433396 describes a block ofprocessed cheese or processed cheese product, which is coated with asurface layer of Camembert or Roquefort mould in order to provide aharder rind, and thus enhance shape and storage stability. In apreferred embodiment, layers of a natural cheese such as a blue veincheese or a second processed cheese or processed cheese product areincorporated into the processed cheese block. However, the productdescribed in the specification is not what would normally be referred toas a surface-ripened cheese, as there is no modification of flavour ortexture of the starting processed cheese material.

U.S. Pat. No. 4,911,935by Bongrain S. A. describes a food productComprising a mass of cheese having a semi-permeable external envelopecovering its exterior surface, on which a surface mould may be grown toimprove maturation of the cheese without rapid degradation. Thesemi-permeable layer is a food gel, preferably carrageenan, an alginate,gelatin, food protein, or a mixture thereof.

European Patent No. 33635 by C.P.C. International Inc. describes apackaged cheese spread based on a natural cheese, in which the naturalcheese is combined with an edible fat and a stabilising agent, heated,mixed and poured into containers, and then coated with an edible barriermaterial which forms an impermeable film over the cheese spread surface,and then inoculated with Penicillium camemberti to form a camembert-typecrust.

Czechoslovak Patent No. 249009 describes a process of manufacturing asurface-ripened cheese in which the surface of a naturally ripeningcheese, of unspecified origin, is pasteurised in a saline solution at75° to 90° C. and then inoculated with a culture of lactic fermentationbacteria together with a culture of Penicillium camemberti, in order toform a surface layer which prevents the growth of undesirablemicroorganisms, thus avoiding the need fro the cheese surface to bescraped or washed before marketing. It appears that this product may notundergo any maturation of flavour.

However, most surface-ripened cheeses on the market are of theCamembert, Brie, or Chevre types, prepared using traditional methods.

The shelf life of most such surface-ripened cheeses is in the range of 6to 10 weeks. So far, the only practicable way in which this shelf lifecan be extended has been by canning the cheese, which results in aproduct with reduced consumer appeal.

We have now found it possible to produce a surface-ripened product whichhas an improved shelf life (greater than 20 weeks, and usually 25 to 30weeks) and which does not suffer any loss in consumer appeal over thisextended shelf life, without the need to employ an impermeable orpermeable external layer, or to use an additional culture inoculumfollowing a pasteurisation step.

We have surpisingly found that by using a stable natural cheese as astarting product, applying a surface-ripening culture to the outsidesurface of the cheese, and incubating under carefully controlledconditions, the resulting product has considerably extended shelf life.By using an existing stable cheese as substrate for the surface-ripeningculture a stable base is provided, which resists breakdown by thesurface-ripening culture:

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided asurface-ripened cheese product prepared from a stable natural cheesebase, and having extended shelf life.

According to a second aspect of the invention, there is provided amethod of making a surface-ripened cheese product, comprising the stepof applying a surface-ripening culture to the outside surface of astable natural cheese base, and incubating under controlled conditions.

Suitable surface-ripening cultures are of the type generally describedas being of the `white mould` type, but are not necessarily white. Theywill grow substantially only on the exposed surface of the naturalcheese base, and will not break down the body of the cheese. They will,of course, be non-toxic, and be able to produce an organolepticallydesirable product. The culture must be able to grow in the pH range ofthe natural cheese base, which is generally but not necessarily about pH4.9 to about pH 5.4.

Most of the surface-ripening cultures which are presently widely used inthe art grow optimally at 8° to 18° C., and at relative humidity 90% to100%, but these are not specific requirements for cultures suitable foruse in this invention.

Preferably, the surface-ripening culture is Penicillium candidum orPenicillium camemberti, but other suitable mould varieties can be used,and are known to those skilled in the art.

The culture conditions are not critical, except insofar as they mustsupport the growth of the surface-ripening culture.

Preferably the temperature of incubation is between 8° and 18° C., morepreferably 10° C.

Preferably the humidity during incubation is 90 to 100%, more preferably95 to 100%.

Preferably the natural cheese base is selected from the group consistingof normal, reduced fat or lower fat:

Eyed types, such as Edam and Swiss

Italian types, such as Mozzarella

Danish types, such as Havarti and other similar varieties,

as well as reduced fat or lower fat varieties of any of these.

The cheese must be of a type which is inherently stable both chemicallyand microbiologically, ie. susceptible only to limited surface growth ofthe ripening culture, so that the ripening culture cannot significantlypenetrate the body of the cheese, and affects substantially only thesurface of the cheese. It must be able to produce an organolepticallydesirable product, and must not contain added preservative which wouldprevent growth of the surface-ripening culture. Suitable cheese typeswill generally, but not exclusively, be products which are freshly madeand are not susceptible to rapid attack and breakdown bysurface-ripening cultures.

The natural cheese base may be in any desired shape or thickness, sincethe surface-ripening culture does not have to penetrate the wholeproduct, in contrast to convention surface-ripened cheese of the Brie orCamembert type.

DETAILED DESCRIPTION OF THE INVENTION

The natural cheese base is prepared by technology appropriate for thevariety under consideration, and is then cut to the shape required forthe surface-ripened product.

The cheese is then inoculated with a suspension of the surface-ripeningculture, preferably by spraying, and is incubated under conditions ofcontrol temperature and humidity until good mould growth has beenachieved. The cheese may be turned and culture suspension reapplied inorder to ensure even coverage of mould.

When good mould growth has been achieved, the finished product may bepacked in a suitable wrapping material, for example paper-linedperforated plastic film, such as is typically used for surface-ripenedcheese.

Although the surface-ripening culture is preferably applied by spraying,other coating methods such as dipping may alternatively be used.

The cheese product will remain in good condition for more than 20 weeks,preferably 25 to 30 weeks, under appropriate refrigerated storage,typically at 2° C. to 5° C.

The invention will be further illustrated by way of reference only tothe following non-limiting examples.

Example 1 Cheddar-Based Surface-Ripened Cheese

The surface-ripened product was made from Cheddar cheese in accordancewith the following steps:

1. Cheddar cheese of 2 to 4 weeks of age was selected, ensuring that noflavour defects were present;

2. The Cheddar cheese was cut to the shape and size desired for thefinished product;

3. The cheese was sprayed with a suspension of Penicillium candidum, andstored on racks in a controlled atmosphere maturing room. Thetemperature was between 8° and 18° C., typically 10° C. The humidity wasbetween 95 and 100%;

4. After 2 days of incubation, the cheese was turned, and re-sprayedwith culture. This step may optionally be repeated after another 2 days;

5. When good even mould coverage had been achieved, typically by 7 to 14days, the cheese was removed from the maturing room, wrapped and placedin cartons, and placed in refrigerated storage at 2° C. to 5° C. Underthese conditions, the cheese was found to have a shelf life of 25 to 30weeks.

A surface-ripened cheese product made from Chedder cheese using themethod described above had the following typical composition:

    ______________________________________                                               Product       Amount                                                   ______________________________________                                               Water         37.0%                                                           Fat           33.0%                                                           Protein       26.0%                                                           Salt           1.8%                                                           Lactose       trace                                                           Ash            3.5%                                                           Sodium        9800 ppm                                                        Potassium     1000 ppm                                                        Calcium       7400 ppm                                                        Phosphorus    5300 ppm                                                 ______________________________________                                    

Example 2 Colby-Based Surface-Ripened Cheese

The surface-ripened product was made from Colby cheese in accordancewith the following steps:

1. Colby cheese was selected at 2-4 weeks of age, ensuring that noflavour defects were present;

2. The Colby cheese was cut to the shape and size desired for thefinished product;

3. The cheese was sprayed with a suspension of Penicillium camemberti,and stored on racks in a controlled atmosphere maturing room. Thetemperature was between 8° and 18° C., typically 10° C., and thehumidity was between 95% and 100%;

4. After 2 days of incubation, the cheese was turned, and re-sprayedwith culture. This step may optionally be repeated after another 2 days;

5. When good even mould coverage had been achieved, typically by 7 to 14days, the cheese was removed from the maturing room, wrapped and .placedin cartons, and placed in refrigerated storage at 2° to 5° C. Underthese conditions, the cheese was found to have a shelf life of 25 to 30weeks.

A surface-ripened cheese product made from Colby cheese using the methoddescribed in Example 2 had the following typical composition:

    ______________________________________                                               Product       Amount                                                   ______________________________________                                               Water         38.0%                                                           Fat           34.0%                                                           Salt           1.8%                                                           pH             5.1%                                                           Protein       23.0%                                                           Lactose       trace                                                           Ash            3.5%                                                           Sodium        9800 ppm                                                        Potassium     1000 ppm                                                        Calcium       7400 ppm                                                        Phosphorus    5300 ppm                                                 ______________________________________                                    

Example 3 Edam-Based Surface-Ripened Cheese

The surface-ripened product was made from Edam cheese in accordance withthe following steps:

1. Edam cheese of 2 to 4 weeks of age was selected, ensuring that nocompositional or flavour defects were present;

2. The Edam cheese was cut to the shape and size desired for thefinished product;

3. The cheese was sprayed with a suspension of Penicillium candidum, andstored on racks in a controlled atmosphere maturing room. Thetemperature was between 8° C. and 18° C., typically 10° C., and thehumidity was between 95 and 100%;

4. After 2 days of incubation, the cheese was turned and re-sprayed withculture. This step may optionally be repeated after another 2 days;

5. When good even mould coverage had been achieved, typically by 7 to 14days, the cheese was removed from the maturing room, wrapped and placedin cartons, and placed in refrigerated storage at 2° to 5° C. Underthese conditions, the cheese was found to have a shelf life of 25 to 30weeks.

A surface-ripened cheese product made from Edam cheese using the methodof Example 3 had the following typical composition:

    ______________________________________                                        Product              Amount                                                   ______________________________________                                        Water                39.0%                                                    Fat                  25.0%                                                    Salt                  1.9%                                                    pH                    5.1%                                                    Protein              26.0%                                                    Lactose              trace                                                    Ash                   3.5%                                                    Sodium               10100 ppm                                                Potassium             1500 ppm                                                Calcium               8700 ppm                                                Phosphorus            7600 ppm                                                ______________________________________                                    

The products of Examples 1, 2 and 3 have a fluffy white exteriorsurface, stay firm, and have a pleasant mild cheese flavour, with adistinctive "camembert" note.

It will be clearly understood that the invention in its general aspectsis not limited to the specific details referred to hereinabove.

I claim:
 1. A surface-ripened cheese product having a shelf life of atleast 20 weeks at 2° C. to 5° C., prepared from a stable natural cheesebase wherein a surface-ripening culture selected from the groupconsisting of Penicillium candidum and Penicillium camemberti is appliedto the outside surface of said stable natural cheese base.
 2. Asurface-ripened cheese product according to claim 1, in which thenatural cheese base is selected from the group consisting of fat Englishtypes, eyed types, Italian types, and Danish types.
 3. A surface-ripenedcheese product according to claim 1, in which the natural cheese base isselected from the group consisting of Cheddar, Colby, Cheshire, Edam,Swiss, Mozzarella and Havarti.
 4. A method of making a surface-ripenedcheese product having a shelf life of at least 20 weeks at 2° C. to 5°C., comprising the step of applying a surface-ripening culture selectedfrom the group consisting of Penicillium candidum and Penicilliumcamemberti to the outside surface of a stable natural cheese base, andincubating under controlled conditions.
 5. A method of making asurface-ripened cheese product according to claim 4, wherein the flavourand/or texture of the natural cheese base is modified to produce thesurface-ripened cheese, and wherein the stable natural cheese base isnot significantly penetrated by the surface-ripening culture.
 6. Amethod according to claim 4 in which the natural cheese base is selectedfrom the group consisting of fat English types, eyed types, Italiantypes and Danish types.
 7. A method according to claim 4 in which thenatural cheese base is selected from the group consisting of Cheddar,Colby, Cheshire, Edam, Swiss, Mozzarella and Havarti.
 8. A method ofmaking a surface-ripened cheese product according to claim 4 comprisingthe steps of:(a) applying the surface-ripening culture by spraying; (b)incubating at a temperature of 8° C. to 18° C. at a humidity of 95° C.to 100%, for 7 to 14 days; and (c) storing at 2° C. to 5° C.
 9. A methodaccording to claim 4 in which the surface-ripening culture is applied byspraying one or more times during incubation.